I don't believe that everyone should be eating the same diet.
We're all different and what works for one person may not work for the next.
Different strokes for different folks.
However, a large portion of the population stands to benefit from a low-carb diet.
In fact, there are very few things in nutrition that are as rigorously proven to be effective as carb restricted diets for those who are:
- Overweight or obese.
- Type II diabetic.
- Have the metabolic syndrome.
For these disorders, we have at least 21 randomized controlled trials that prove, without a shadow of a doubt, that carb restricted diets yield better results than the low-fat diet that is commonly prescribed.
Here are 7 reasons to choose low-carb over low-fat, backed by science.
In studies where low-fat and low-carb diets are compared, the carb restricted dieters are often allowed to eat until fullness, while the fat restricted groups need to count calories and control portions.
Despite that, the low-carb dieters tend to eat the same amount or even fewer calories than the low-fat groups due to appetite reducing effects of the diet ().
Therefore, low-carb diets lead to automatic weight loss. There is no need to control portions as long as the carbs are kept low ().
Bottom Line: Unlike low-fat dieters, low-carb eaters don't need to control portions or count calories. Eating fewer carbs leads to an automatic reduction in appetite and weight loss without much effort.
Carb restriction almost invariably leads to greater weight loss than diets that are reduced in fat. Sometimes the difference is small, while other times 2-3 times as much fat is lost ().
When it has been tested, it is noted that a greater proportion of the fat lost came from the abdominal area in low-carb dieters.
This means that the deep visceral fat, highly associated with diabetes, heart disease and an unflattering appearance, is especially vulnerable to the fat burning effects of low carbohydrate diets ().
Bottom Line: Low-carb eaters lose more weight compared to people on low-fat diets. Low-carb is particularly effective at reducing belly fat.
For that reason, it seems intuitive that low-carb diets would lead to a reduction in triglycerides, while low-fat diets should increase them.
This is indeed the case. Low-carb diets drastically reduce triglycerides, while low-fat diets either don't improve them very much or literally make them worse (, ).
Bottom Line: Low-carb diets decrease triglyderides, fat molecules that are linked to increased risk of heart disease when elevated.
Levels of HDL cholesterol (the "good" cholesterol) are an important preventative factor for heart disease.
Put simply, HDL transports cholesterol away from the peripherals of the body and towards the liver for reuse or excretion.
Another important effect of low-carb diets is that they raise HDL levels, while low-fat diets tend to increase them less or even decrease them.
The triglyceride:HDL ratio is a very reliable marker for insulin resistance, metabolic syndrome and risk of heart disease (, ).
Therefore, if anything, low-carb diets should be much better for your heart and your overall health than the low-fat diet that still governs mainstream recommendations.
Bottom Line: Low-carb diets are more effective at increasing HDL cholesterol than low-fat diets, which may even decrease HDL in some cases.
Concentration of LDL, the "bad" cholesterol, is the one risk factor that doesn't appear to improve much on low-carb diets. There is a lot of individual variation here, and in some cases LDL cholesterol even increases slightly on a low-carb diet.
However, the picture is a little more complicated than some people may think.
There is more than one form of LDL. Primarily, we have both the small, dense LDL molecules that are kind of like little BB gun bullets. They oxidize easily and penetrate the walls of arteries.
Then we have the large, fluffy LDL molecules that are a little bit like furry cotton balls. They don't tend to lodge in the arteries and cause heart disease.
One important risk factor is whether LDL molecules are primarily of the small, dense type (pattern B) or the large, fluffy type (pattern A). The small, dense particles are bad, while the large, fluffy ones are good (, , ).
On low-carb diets, these pattern shift away from pattern B (B = Bad) to Pattern A (A = Awesome).
So in reality, even though low-carb diets don't lead to an actual reduction in total LDL, they do appear to turn the LDL molecules into forms that are benign (, ).
Bottom Line: While low-carb diets don't decrease concentration of LDL cholesterol, they do seem to improve the form of the molecules so that they are less harmful.
The group that stands to benefit the most from low-carb diets are diabetics.
Diabetics have an inability to shuttle glucose into cells. Carbs = glucose, and excess glucose in the bloodstream is toxic.
Less carbs = less glucose for the diabetics. This leads to lower blood sugar levels and less need for insulin and glucose-lowering medication.
In many cases, low-carb diets appear to cure the serious disease known as type II diabetes.
Some doctors that routinely prescribe these diets in practice can often decrease insulin by 50% on the first day of the diet, then many patients can reduce or even stop taking medication (effectively cured) in a matter of weeks or months (, , ).
That being said, if you are diabetic, you should always consult with a medical professional before making any dietary changes.
Bottom Line: Eating a low-carb diet can improve blood sugar control and decrease medication needs in diabetics. Some people with type II diabetes are even able to stop taking medication after some time on the low-carb diet.
Low-carb diets restrict entire food groups, which some people think is impossible.
However, low-carb diets actually appear to be easier to stick to than low-fat diets.
This means that out of the people who are assigned to the carb restricted diet, more people actually tend to make it to the end of the study (, ).
Bottom Line: It's a myth that low-carb diets are harder to stick to than low-fat diets. In fact, studies find that people are more likely to finish the study period on a low-carb diet.
There are many reasons why you should try a low-carb instead of a low-fat diet.
Low-carb eaters tend to eat fewer calories and feel less hungry. They also lose more weight compared to low-fat eaters.
Eating a low-carb diet also improves many risk factors for type 2 diabetes and heart disease.
In fact, low-carb diets are among the easiest, healthiest and most effective ways to lose weight and improve metabolic health.